Texas Septic Inspector Certification —
Advanced Level
230 Practice Questions with Correct Answers & Rationales
Topics Covered: OSSF Regulations & TCEQ Rules, Soil Evaluation & Site Assessment,
System Design & Sizing, Installation Standards, Aerobic Treatment Units, Alternative Systems,
Maintenance & Inspection, Pumping Systems, Setback Requirements, Failing Systems, Water
Quality, Math Calculations & Advanced Concepts
SECTION 1: Texas OSSF Regulations & TCEQ Authority
1. The primary state agency responsible for regulating On-Site Sewage Facilities (OSSFs) in
Texas is:
A) Texas Department of State Health Services (DSHS)
B) Texas Commission on Environmental Quality (TCEQ)
C) Texas Department of Agriculture
D) Texas Water Development Board (TWDB)
(Correct Answer: B) Rationale: TCEQ administers the Texas OSSF program under 30 TAC
Chapter 285, setting standards for design, installation, inspection, and maintenance of all OSSFs
in Texas.
2. The primary state rule governing OSSFs in Texas is found in:
A) 30 TAC Chapter 217
B) 30 TAC Chapter 285
C) 30 TAC Chapter 210
D) Texas Health & Safety Code Chapter 366
(Correct Answer: B) Rationale: 30 TAC Chapter 285 is the comprehensive TCEQ rule
governing OSSF design, installation, inspection, permitting, and maintenance — the
foundational document for all Texas OSSF work.
3. Under Texas law, which entity has "authorized agent" authority to administer the OSSF
program locally?
, A) A licensed plumber
B) A county or municipality that has adopted the TCEQ OSSF rules
C) Any registered sanitarian
D) The local water utility district
(Correct Answer: B) Rationale: Counties and municipalities may become "authorized agents"
of TCEQ by adopting the state OSSF rules — they then issue permits, conduct inspections, and
enforce compliance locally.
4. When a county has NOT become an authorized agent, OSSF permitting authority lies with:
A) The local health department
B) TCEQ directly
C) The adjacent authorized agent county
D) The property owner's engineer of record
(Correct Answer: B) Rationale: In counties without an authorized agent, TCEQ retains direct
permitting and enforcement authority for all OSSFs.
5. Under 30 TAC Chapter 285, a site evaluation for a conventional OSSF must be performed by:
A) Any licensed plumber
B) A licensed professional engineer (PE), registered sanitarian (RS), or licensed OSSF
installer with appropriate endorsements
C) The property owner if they have a high school diploma
D) Any TCEQ-registered inspector
(Correct Answer: B) Rationale: Site evaluations must be performed by qualified professionals
— PEs, registered sanitarians, or appropriately licensed OSSF professionals — to ensure
accurate soil and site assessment.
6. Which of the following OSSF activities requires a permit in Texas?
A) Pumping a septic tank
B) Installing, repairing, or modifying an OSSF
C) Inspecting an existing OSSF for a real estate transaction
D) Replacing a manhole cover on an existing tank
(Correct Answer: B) Rationale: Installation, repair, or modification of OSSFs requires a permit
from the authorized agent or TCEQ — unpermitted work is a violation of 30 TAC 285.
,7. Texas Health and Safety Code Chapter 366 requires that all new OSSFs:
A) Use aerobic treatment units exclusively
B) Be designed, installed, and maintained to protect public health and prevent water
pollution
C) Be inspected annually by TCEQ
D) Have a minimum tank capacity of 1,500 gallons
(Correct Answer: B) Rationale: Chapter 366 establishes the statutory authority and broad
requirements for OSSF regulation in Texas — protecting public health and preventing
contamination of water resources.
8. In Texas, an OSSF maintenance provider must be:
A) A licensed electrician
B) Licensed by TCEQ as a maintenance company or technician for the specific system
type
C) Employed by the county health department
D) A registered engineer only
(Correct Answer: B) Rationale: TCEQ requires OSSF maintenance companies and technicians
to be licensed for specific system types — ensuring competent maintenance of complex systems
like ATUs.
9. The TCEQ OSSF program requires that aerobic treatment units (ATUs) have a maintenance
contract for a minimum of:
A) 1 year
B) 2 years
C) 5 years
D) The life of the system
(Correct Answer: B) Rationale: 30 TAC 285 requires ATUs to have a maintenance contract
with a licensed provider for a minimum of 2 years — renewable thereafter to ensure ongoing
proper operation.
10. Which of the following requires an OSSF to be replaced rather than repaired?
, A) A cracked distribution box lid
B) A failed drainfield that cannot be rehabilitated and has no suitable area for repair or
expansion
C) A septic tank with a missing baffle
D) A broken cleanout cap
(Correct Answer: B) Rationale: When the original drainfield fails and no suitable area exists
for repair or expansion, the entire OSSF must be replaced — typically requiring a new site
evaluation and permit.
11. Under 30 TAC 285, who is responsible for ensuring an OSSF is maintained in proper
working order?
A) The OSSF installer
B) The property owner
C) The authorized agent
D) The licensed maintenance company
(Correct Answer: B) Rationale: Ultimate responsibility for proper OSSF maintenance lies with
the property owner — though they may contract a licensed maintenance provider, the legal
obligation remains with the owner.
12. A "nuisance" condition created by a failing OSSF in Texas is defined as:
A) Any system older than 20 years
B) A condition that creates a public health hazard, offensive odors, or surface discharge
of sewage
C) A system without a current maintenance contract
D) A system with a septic tank older than 10 years
(Correct Answer: B) Rationale: Surface discharge, sewage odors, and public health risks from
a failing OSSF constitute a nuisance under Texas law — subject to enforcement action and
required remediation.
SECTION 2: Soil Evaluation & Site Assessment
13. The purpose of a soil profile examination in OSSF site assessment is to:
A) Determine the pH of the soil for landscaping
Advanced Level
230 Practice Questions with Correct Answers & Rationales
Topics Covered: OSSF Regulations & TCEQ Rules, Soil Evaluation & Site Assessment,
System Design & Sizing, Installation Standards, Aerobic Treatment Units, Alternative Systems,
Maintenance & Inspection, Pumping Systems, Setback Requirements, Failing Systems, Water
Quality, Math Calculations & Advanced Concepts
SECTION 1: Texas OSSF Regulations & TCEQ Authority
1. The primary state agency responsible for regulating On-Site Sewage Facilities (OSSFs) in
Texas is:
A) Texas Department of State Health Services (DSHS)
B) Texas Commission on Environmental Quality (TCEQ)
C) Texas Department of Agriculture
D) Texas Water Development Board (TWDB)
(Correct Answer: B) Rationale: TCEQ administers the Texas OSSF program under 30 TAC
Chapter 285, setting standards for design, installation, inspection, and maintenance of all OSSFs
in Texas.
2. The primary state rule governing OSSFs in Texas is found in:
A) 30 TAC Chapter 217
B) 30 TAC Chapter 285
C) 30 TAC Chapter 210
D) Texas Health & Safety Code Chapter 366
(Correct Answer: B) Rationale: 30 TAC Chapter 285 is the comprehensive TCEQ rule
governing OSSF design, installation, inspection, permitting, and maintenance — the
foundational document for all Texas OSSF work.
3. Under Texas law, which entity has "authorized agent" authority to administer the OSSF
program locally?
, A) A licensed plumber
B) A county or municipality that has adopted the TCEQ OSSF rules
C) Any registered sanitarian
D) The local water utility district
(Correct Answer: B) Rationale: Counties and municipalities may become "authorized agents"
of TCEQ by adopting the state OSSF rules — they then issue permits, conduct inspections, and
enforce compliance locally.
4. When a county has NOT become an authorized agent, OSSF permitting authority lies with:
A) The local health department
B) TCEQ directly
C) The adjacent authorized agent county
D) The property owner's engineer of record
(Correct Answer: B) Rationale: In counties without an authorized agent, TCEQ retains direct
permitting and enforcement authority for all OSSFs.
5. Under 30 TAC Chapter 285, a site evaluation for a conventional OSSF must be performed by:
A) Any licensed plumber
B) A licensed professional engineer (PE), registered sanitarian (RS), or licensed OSSF
installer with appropriate endorsements
C) The property owner if they have a high school diploma
D) Any TCEQ-registered inspector
(Correct Answer: B) Rationale: Site evaluations must be performed by qualified professionals
— PEs, registered sanitarians, or appropriately licensed OSSF professionals — to ensure
accurate soil and site assessment.
6. Which of the following OSSF activities requires a permit in Texas?
A) Pumping a septic tank
B) Installing, repairing, or modifying an OSSF
C) Inspecting an existing OSSF for a real estate transaction
D) Replacing a manhole cover on an existing tank
(Correct Answer: B) Rationale: Installation, repair, or modification of OSSFs requires a permit
from the authorized agent or TCEQ — unpermitted work is a violation of 30 TAC 285.
,7. Texas Health and Safety Code Chapter 366 requires that all new OSSFs:
A) Use aerobic treatment units exclusively
B) Be designed, installed, and maintained to protect public health and prevent water
pollution
C) Be inspected annually by TCEQ
D) Have a minimum tank capacity of 1,500 gallons
(Correct Answer: B) Rationale: Chapter 366 establishes the statutory authority and broad
requirements for OSSF regulation in Texas — protecting public health and preventing
contamination of water resources.
8. In Texas, an OSSF maintenance provider must be:
A) A licensed electrician
B) Licensed by TCEQ as a maintenance company or technician for the specific system
type
C) Employed by the county health department
D) A registered engineer only
(Correct Answer: B) Rationale: TCEQ requires OSSF maintenance companies and technicians
to be licensed for specific system types — ensuring competent maintenance of complex systems
like ATUs.
9. The TCEQ OSSF program requires that aerobic treatment units (ATUs) have a maintenance
contract for a minimum of:
A) 1 year
B) 2 years
C) 5 years
D) The life of the system
(Correct Answer: B) Rationale: 30 TAC 285 requires ATUs to have a maintenance contract
with a licensed provider for a minimum of 2 years — renewable thereafter to ensure ongoing
proper operation.
10. Which of the following requires an OSSF to be replaced rather than repaired?
, A) A cracked distribution box lid
B) A failed drainfield that cannot be rehabilitated and has no suitable area for repair or
expansion
C) A septic tank with a missing baffle
D) A broken cleanout cap
(Correct Answer: B) Rationale: When the original drainfield fails and no suitable area exists
for repair or expansion, the entire OSSF must be replaced — typically requiring a new site
evaluation and permit.
11. Under 30 TAC 285, who is responsible for ensuring an OSSF is maintained in proper
working order?
A) The OSSF installer
B) The property owner
C) The authorized agent
D) The licensed maintenance company
(Correct Answer: B) Rationale: Ultimate responsibility for proper OSSF maintenance lies with
the property owner — though they may contract a licensed maintenance provider, the legal
obligation remains with the owner.
12. A "nuisance" condition created by a failing OSSF in Texas is defined as:
A) Any system older than 20 years
B) A condition that creates a public health hazard, offensive odors, or surface discharge
of sewage
C) A system without a current maintenance contract
D) A system with a septic tank older than 10 years
(Correct Answer: B) Rationale: Surface discharge, sewage odors, and public health risks from
a failing OSSF constitute a nuisance under Texas law — subject to enforcement action and
required remediation.
SECTION 2: Soil Evaluation & Site Assessment
13. The purpose of a soil profile examination in OSSF site assessment is to:
A) Determine the pH of the soil for landscaping
